Payment method configuration

[hassanegenius]

Hi,, Good morning to All    i have problem with payment method configuration. i am using virtual mart . and i set up Paypal sandbox from Joomla dashboard.
but in front view , when i choose a product for pay with Paypal payment method, its don't shows me last stage!. Just redirect me previous page for choosing payment method.
i do not understand , where is my wrong?  is there problem with template or my settings??

i also try with default payment system, but same result.

Please , any help will be appreciate.

my joomla version is  :Joomla! 2.5.17
virtual mart version is :  2.0.26d

Thanks

[jenkinhill]

Use the current Joomla/ VM versions - 2.5.22/2.6.6  (test updates on a backup of the site first).

[hassanegenius]

Hi,, Thanks for your suggestion.  i am really scared to do update. if i lost my all works!!

now i am going to update both, then  i will tell you what happened!

[hassanegenius]

I solved this issues! There was a problem in admin panel. which is enable single page checkout . i just deselect this option .. and then its solved .

Thanks